Radial ball joint

ABSTRACT

A radial ball-and-socket joint is provided with a housing. A bearing shell ( 2 ) in the housing rotatably and tiltably accommodates a joint ball ( 4 ). The joint ball is part of a ball pivot ( 3 ). The ball pivot also has a shaft ( 5 ), which projects through a outlet opening ( 6 ) of the housing ( 1 ). The housing is closed with a cover ( 7 ) on the side opposite the outlet opening ( 6 ). The bearing shell ( 2 ), accommodated in the housing in a positioned manner, has an axially extending continuous slot ( 8 ). The cover ( 7 ), arranged between the cover and the bearing shell, has a geometry ( 9 ) impressed into a damping element ( 11 ) on its inner side facing the bearing shell. As a result of the construction the damping element ( 11 ) and the bearing shell are fixed in the housing ( 1 ).

FIELD OF THE INVENTION

The present invention pertains to a radial ball-and-socket joint with ahousing, in which a bearing shell rotatably and tiltably accommodates ajoint ball. The joint ball is part of a ball pivot. The ball pivot alsohas a shaft, which projects through an outlet opening of the housing.The housing is closed with a cover on the side opposite the outletopening.

BACKGROUND OF THE INVENTION

Radial ball-and-socket joints are loaded predominantly in the radialdirection and are used mainly for wheel suspensions in motor vehicles.Such a radial ball-and-socket joint known from the state of the artcomprises a housing in which a bearing shell rotatably and tiltablyreceives a joint ball of a ball pivot. The ball pivot also has a shaft,which projects from the housing through an outlet opening. The housingis closed with a cover on the side opposite the outlet opening.

A ball-and-socketjoint in which the bearing shell is traversed by a slotextending at right angles to the circumferential direction has beenknown from DE 42 11 897 A1.

Furthermore, DE 43 05 994 A1 discloses a bearing shell on thehousing-side contact surfaces of which ribs are made in one piece, whichbring about a specific mounting characteristic of the joint ball of theball pivot.

One problem that keeps arising especially in radially loadedball-and-socket joints is, on the one hand, that a possibility ofmounting the joint ball is to be provided which sufficiently meets theloads that occur. The contact surface between the joint ball and theinner surface of the bearing shell shall not possibly have anyinterruptions for this. On the other hand, the lowest possible frictionis required between the bearing shell and the joint ball. However, itwould be necessary for this to possibly permit only small contactsurfaces between the joint ball and the inner surface of the bearingshell. This apparent contradiction cannot be sufficiently solved withthe prior-art ball-and-socket joint designs.

Moreover, it is disadvantageous in prior-art designs that the bearingshell can rotate automatically within the housing. As a result, optimalpositioning of the bearing shell, which is performed at the time of thefirst assembly with respect to the loads to be expected, is no longergiven, and the ball joint is subject to more rapid wear or it no longermeets the necessary requirements.

SUMMARY AND OBJECTS OF THE INVENTION

The basic technical object of the present invention is to provide aradial ball-and-socket joint that can handle the loads occurring mainlyin the radial direction and has only a slight friction between thebearing shell and the joint ball of the ball pivot. At the same time,automatic rotation of the bearing shell in the housing shall beprevented from occurring.

According to the invention, a radial ball-and-socket joint is providedwith a housing, in which a bearing shell rotatably and tiltablyaccommodates a joint ball. The joint ball is part of a ball pivot. Theball pivot also has a shaft, which projects through an outlet opening ofthe housing. The housing is closed with a cover on a side opposite theoutlet opening. The bearing shell, accommodated in the housing in apositioned manner, has an axially extending continuous slot and thecover has a geometry impressed into a damping element arranged betweenthe cover and the bearing shell on its inner side facing the bearingshell. As a result of this the damping element and the bearing shell arefixed in the housing.

Thus, the radial ball-and-socket joint according to the presentinvention has a bearing shell with a continuous slot extending axiallyrelative to the central axis of the bearing shell.

In addition, a geometry be provided in the cover closing the housing onthe side of the cover facing the bearing shell or made integrally withthe cover. This geometry is impressed into a damping element presentbetween the surface of the bearing shell and the underside of the cover.This geometry may be, e.g., a wave-shaped, cam-shaped or sawtooth-likecontour.

During the assembly of the joint, the bearing shell is first pulled overthe joint ball and is subsequently inserted into the housing in apredetermined fitting position. This fitting position can be determinedby means of simple markings provided on the housing.

To make it possible to close the radial ball-and-socket joint with thecover, the cover is placed on the closure-side opening, so that it isimpressed with its above-mentioned geometry into the damping element, asa result of which a gentle axial pretension is applied via the dampingelement to the bearing shell, which ultimately represents a very simplemeans of securing the bearing shell and the damping element againstrotation.

The positioned fitting position of the bearing shell is of particularsignificance for preventing the slot from being located in the principaldirection of load of the radial ball-and-socket joint. The fittingposition can be defined highly accurately because there is only oneprincipal direction of load, which is arranged opposite the slot, inball-and-socket joints in according to the present invention.

The friction within thejoint was also reduced substantially by thedesign of a radial ball-and-socket joint according to the presentinvention because the bearing shell can be placed on the joint ball ofthe ball pivot under an extremely weak centripetal pressure as aconsequence of the axially continuously arranged slot in the bearingshell.

A gentle axial pretensioning force is applied to the bearing shell dueto the cover closing the housing, where a damping element may also beprovided on the inner side of the cover The contact surfaces between thejoint ball and the inner surface of the bearing shell are reduced bysuch a design, as is the pressing force of the bearing shell against thejoint ball. The joint is subject, on the whole, to very little wearbecause there is hardly any friction between the joint ball and thebearing shell surface accommodating it.

Furthermore, compensation of manufacturing tolerances of the individualcomponents and of the dimensional tolerances occurring in the joint dueto temperature differences is achieved by means of a ball-and-socketjoint according to the present invention, and so is a compensation ofwear-related tolerances which become established over the course of timein every joint and frequently lead to it becoming unfit for use.

According to another embodiment ofthe present invention, the bearingshell is provided with circumferentially arranged ribs on the sidefacing the cover. Besides improving the securing of the bearing shellagainst rotation, these ribs also make it possible to obtain a freelyselectable, axial damping characteristic of the bearing shell as afunction of the geometry of the ribs.

To avoid a spontaneous movement of the damping element and/or thebearing shell within the radial ball-and-socket joint, it is possibleaccording to the present invention, on the one hand, to provide acontact surface on the inside of the cover for the damping element,which has a geometric profile which is impressed into the dampingelement after the closing of the housing, or to make the cover and thedamping element in one piece.

In the case of a one-piece design, the damping element may be vulcanizedas a rubber ring directly on the cover or be subsequently bonded to thecover or be fastened to it in another way.

The rubber ring forming the damping element may have various crosssections, e.g., in a round, rectangular or square cross section in sucha solution.

To meet the requirement in terms of low static friction and low momentof friction of the bearing shell-joint ball pair, it is, furthermore,proposed that the spherical inner bearing surface of the bearing shellbe provided with a circumferential recess in the equatorial area.Moreover, the inner bearing surface of the bearing shell may have aplurality of grease pockets in the form of simple geometric recesses.The contact areas between the bearing shell and the joint ball are thusreduced to a minimum in terms of both their number and their area.Recesses of various types and geometry as well as arrangement may, ofcourse, be provided within the spherical inner bearing surface of thebearing shell.

However, the recesses always have a depth that is so small that when aradially directed load is applied to thejoint ball, thejoint ball willimmediately come into contact with the bottom of the recess and fullloading of the bearing is thus achieved in a short time.

As a result, it was possible to achieve an increase in the loadabilityof the joints according to the present invention while reducing thefriction at the same time.

The features of the present invention, which were mentioned above andwill be explained below, may, of course, be used not only in theparticular combination described but also in other combinations,additionally or alone, without going beyond the scope of the presentinvention.

A preferred embodiment of a radial ball-and-socket joint according tothe present invention will be explained in greater detail below withreference to the corresponding drawings.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich a preferred embodiment of the invention is illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a partial sectional view of a radial ball-and-socket joint;

FIG. 2 is an enlarged sectional view of a radial ball-and-socket jointaccording to the present invention;

FIG. 3 is a perspective view of a bearing shell of a radialball-and-socket joint according to the present invention;

FIG. 4A is an enlarged sectional detail view of the cover-side part of aball-and-socket joint; and

FIG. 4B is an enlarged broken away top detail view of the cover-sidepart of a ball-and-socket joint.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings in particular, the radial ball-and-socketjoint shown in the figures has a housing 1, in which a bearing shell 2is accommodated. The joint ball 4 of a ball pivot 3 is accommodatedrotatably and tiltably within the spherical bearing shell inner surface.The shaft 5 made in one piece with the ball pivot 3 exits on one sidethrough an outlet opening 6 of the housing 1. On the side of the housing1 opposite the outlet side, the housing is closed by means of a cover 7.The bearing shell 2 has an axially extending, continuous slot 8according to the present invention and is secured against spontaneousrotation within the housing 1 indirectly by a damping element 11arranged between the cover and the bearing shell. The geometry 9 presentin the cover 7 in the form of a wave-shaped contour is impressed intothe surface of the damping element 11.

As is apparent especially from the view in FIG. 3, the bearing shell 2has web-shaped ribs 10 arranged distributed over the circumference inits area facing the cover 7. These ribs guarantee a freely selectableaxial and/or radial elasticity of the bearing shell 2. Furthermore,recesses 13 forming grease pockets are provided on the spherical innersurface of the bearing shell to reduce the friction of the jointball-bearing shell pair. In addition, a circumferential recess 12 ispresent in the equatorial area of the inner spherical bearing surface ofthe bearing shell 2.

The cover 7 is fastened to the ball-and-socket joint housing 1 by amaterial deformation operation, e.g., by beading or rolling of therolling edge 14 of the housing.

As is apparent from the views in FIGS. 1 and 2, the bearing shell 2 andthe housing 1 receiving the bearing shell also have an outer, sphericalbearing surface on the side on which the pivot exits. The bearing shell2 is thus supported in the housing 1 on this spherical bearing surface.

FIG. 4 shows once again two enlarged details of the closure of the jointin two views in a partial view. A wave-shaped geometry 9 (see upper partof FIG. 4), which is impressed into the damping element 11 during theclosing of the housing, is provided in the underside of the cover 7. Dueto the ribs 10 made in one piece with its top side, the bearing shellalso forms a positive-locking connection with the damping element 11, sothat the bearing shell 2 is fixed in the housing 1 as a result.

The recesses 12 and 13 on the inner bearing surface of the bearing shell2 are not shown in FIGS. 1 and 2 because of the size ratios. Thepretensioning force applied to the bearing shell in the axial directionvia the cover and the damping element 11 made in one piece therewithguarantees that the bearing shell 2 is permanently in contact with thejoint ball 4. Rattling of the ball-and-socket joint is thus ruled out.

Yet, a low-friction ball-and-socket joint which has not been knownbefore from the state of the art in this unique combination is madeavailable as a consequence of the overall design and the combination offeatures according to the present invention.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:
 1. A radial ball-and-socket jomt comprising: ahousing having an outlet opening; a one piece bearing shell disposed insaid housing, said bearing shell being accomodated in said housing in apositioned manner, said bearing shell having edges defining an axiallyextending continuous slot, said edges being circumferentially spacedfrom each other; a joint ball and ball pivot, said joint ball beingrotatably and tiltably accommodated in said bearing shell, said ballpivot having a shaft, which projects through said outlet opening of saidhousing, said bearing shell enclosing said joint ball; a cover closingsaid housing on a side of said housing opposite said outlet opening; adamping eleanent arranged between said cover and said bearing shell onan inner side of said cover facing said bearing shell, said cover havinga geometry impressed into said damping element to fix said dampingelement and said bear shell in said housing.
 2. A radial ball-and-socketjoint in accordance with claim 1, wherein said bearing shell has ribsarranged circumferentially on a side facing said cover, said cover, saiddamping element and said bearing shell interacting to rotationally fixsaid bearing shell relative to said housing in said positioned mannerwhen said cover is connected to said housing, and closes said oppositeopening of said housing.
 3. A radial ball-and-socket joint in accordancewith claim 2, wherein said damping element is flexible and is arrangedbetween said cover and said ribs and applies an axial pretension to thebearing shell.
 4. A radial ball-and-socket joint in accordance withclaim 1, wherein said damping element is vulcanized or bonded to saidcover.
 5. A radial ball-and-socket joint in accordance with claim 4,wherein said damping element is a rubber ring inserted loosely betweensaid cover and said bearing shell; said slot extends completely throughsaid bearing shell in an axial and radial direction of said shaft ofsaid ball pivot.
 6. A radial ball-and-socket joint in accordance withclaim 5, wherein said damping element is one of round, rectangular orsquare in cross section.
 7. A radial ball-and-socket joint in accordancewith claim 4, wherein said bearing shell has a spherical bearing surfacewith a circumferential recess in an equatorial area.
 8. A radialball-and-socket joint accordance with claim 4, wherein said bearingshell has a spherical inner bearing surface with a plurality of recessesforming grease pockets.
 9. A radial ball-and-socket joint comprising: ahousing having an outlet opening; a bearing shell disposed in saidhousing, said bearing shell being accommodated in said housing, saidbearing shell having edges defining an axially extending, continuousslot, said edges being circumferentially spaced from each other, a jointball and ball pivot, said joint ball being rotatably and tiltablyaccommodated in said bearing shell, said ball pivot having a shaft,which projects through said outlet opening of said housing, said bearingshell enclosing said joint ball; a cover closing said housing on a sideof said housing opposite said outlet opening; a damping element arrangedbetween said cover and said bearing shell on an inner side of said coverfacing said bearing shell, said cover having a geometry to bear on saiddamping element to maintain a cicumferential position of said bearingshell in said housing.
 10. A radial ball-and-socket joint in accordancewith claim 9, wherein said bearing shell has ribs arrangedcircumferentially on a side facing said cover.
 11. A radicalball-and-socket joint in accordance with claim 9, wherein said dampingelement is flexible and is arranged between said cover and said ribs andapplies an axial pretension to the bearing shell.
 12. A radialball-and-socket joint in accordance with claim 9, wherein said dampingelement is vulcanized or bonded to said cover.
 13. A radialball-and-socket joint in accordance with claim 9, wherein said dampingelement is a rubber ring inserted loosely between said cover and saidbearing shell.
 14. A radial ball-and-socket joint in accordance withclaim 9, wherein said damping element is one of round, retangular orsquare in cross section.
 15. A radial ball-and-socket joint inaccordance with claim 9, wherein said bearing shell has a sphericalbearing surface with a circumferential recess in an equatorial area. 16.A radial ball-and-socket joint in accordance with claim 9, wherein saidbearing shell has a spherical inner bearing surface with a plurality ofrecesses forming grease pockets.
 17. A radial ball-and-socket jointcomprising: a ball pivot including a joint ball and a shaft; a one piecebearing shell enclosing said joint ball of said ball pivot, said bearingshell including edges defining a slot extending completely through saidbearing shell in an axial and radial direction of said shaft of saidball pivot, said edges being spaced from each other in a circumferentialdirection of said shaft of said ball pivot, said joint ball beingrotatably accommodated in said bearing shell; a housing arranged aroundsaid bearing shell, said housing defining an outlet opening and anopposite opening, said shaft of said ball pivot extending through saidoutlet opening, a damping element arranged at said opposite opening ofsaid housing; a cover connected to said housing and closing saidopposite opening of said housing, said cover, said damping element andsaid bearing shell interacting to fix said bearing shell relative tosaid housing in a predetermined circumferential position when said coveris connected to said housing, and closes said opposite opening of saidhousing.
 18. A radial ball-and-socket joint in accordance with claim 17,wherein: said bearing shell includes ribs arranged circumferentially ona side facing said cover, said ribs interlocking with a shape of saiddamper to fix said bearing shell to said housing in said predeterminedposition; said cover having a shape to interlock with said shape of saiddamper to fix said bearing shell to said housing said predeterminedposition; said cover compressing said damper to distort said damper intosaid shape to interlock said damper with said bearing shell and saidcover.
 19. A radial ball-and-socket joint in accordance with claim 17,where: said bearing shell surrounds an equatorial portion of said jointball.
 20. A radial ball-and-socket joint in accordance with claim 17,wherein: said damper is vulcanized to said cover.